Anim. Syst. Evol. Divers. Vol. 34, No. 3: 174-180, July 2018 https://doi.org/10.5635/ASED.2018.34.3.174

Short communication A New Report of Anthurid Isopod (Crustacea, , ) from Korea

Sung Hoon Kim1, Seong Myeong Yoon2,*

1Department of Life Sciences, College of Natural Sciences, Chosun University, Gwangju 61452, Korea 2Department of Biology, College of Natural Sciences, Chosun University, Gwangju 61452, Korea

ABSTRACT

In this study, Caenanthura engimatica (Kensley and Reid, 1984) is newly reported from Korea along with detailed description and illustrations. This species can be characterized by the following features: cephalon has a rostrum extending as long as anterolateral lobes; pereonites 4-6 have shallow middorsal pits; the mandible palp has 2 articles; article 1 of the mandible palp is twice longer than article 2; and the maxillipedal palp has 1-3 fused and 4-5 fused articles. This is the first report of C. engimatica beyond Arabian Gulf, the type locality, and Indian Ocean. Additionally, we proposed a revised key to known species of the genus Caenathura Kensley, 1978. Keywords: ‌Caenanthura, isopod, morphology, , Korea

INTRODUCTION ular palp has two segmented articles; and the maxilliped is four segmented. However, Wägele (1989) has synonymized The family Anthuridae Leach, 1814 is the oldest and largest Arabanthura with Caenanthura. Thereafter, Poore (2001) group in superfamily Leach, 1814, including confirmed it based on the morphology of maxilliped and 25 genera (Chew et al., 2014). This can be recognized from pereopod 1. In this study, we newly report a Caenathura other Anthuroid isopods by the following characteristics: the species from Korea, C. engimatica, with detailed description body is 10-15 times as long as wide; the flagellum of the and illustrations. This species was originally described from antenna is fewer than ten articles and shorter than the pe­ the Arabian Gulf by Kensley and Reid (1984). The present duncle; the maxillipedal palp has five free articles or some study is the first report of this species from the other region fused articles; each propodus palm of pereopods 4-7 has beyond the Arabian Gulf and the Indian Ocean (WoRMS, single distal robust seta; the exopod of pleopod 1 is opercu­ 2018). We provide a revised key to known species of the liform; the mouthparts are not produced anteriorly; the ple­ genus Caenanthura in this paper. otelson has two statocysts (Poore, 2009). In this family, the Specimens of Caenanthura engimatica were collected genus Caenathura Kensley, 1978 comprises 6 species, Cae- from the southern coast of Korea using a sieve with mesh nathura siamensis (Barnard, 1925), Caenathura indica Ne­ size of 1 mm and the van Veen grab. The collected materials goescu, 1980, Caenathura engimatica (Kensley and Reid, were immediately fixed in 95% ethanol and transferred to 1984), Caenathura gutui (Negoescu, 1997), Caenathura the laboratory. A stereomicroscope (Olympus SZH-ILLD, ibex Bamber, 2008, and Caenathura koreana Song and Min, Japan) and a bright field microscope (Nikon Eclipse 80i, 2015. They can be distinguished from other anthurid isopods Japan) each equipped with a drawing tube were used to by having one or two mandibular palp articles, two or three observe the habitus and appendages. Measurements and il­ maxillipedal articles, and lacking eye (Barnard, 1925; Kens­ lustrations of the specimens were performed with the aid of ley, 1978; Negoescu, 1980; Kensley and Reid, 1984; Nego­ a drawing tube and camera lucida. Examined specimens in escu, 1997; Bamber, 2008; Song and Min, 2015). Kensley this study were deposited at the National Institute of Biolog­ and Reid (1984) have erected the genus Arabanthura by the ical Resources (NIBR) and Chosun University in Korea. following characteristics: the eyes are absent; the mandib­

This is an Open Access article distributed under the terms of the Creative *To whom correspondence should be addressed Commons Attribution Non-Commercial License (http://creativecommons.org/ Tel: 82-62-230-7018, Fax: 82-62-230-7018 licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, E-mail: [email protected] and reproduction in any medium, provided the original work is properly cited. eISSN 2234-8190 Copyright The Korean Society of Systematic Zoology A New Report of Caenanthura from Korea

SYSTEMATIC ACCOUNTS article 2; each article with 1 simple seta distally; molar small and bluntly rounded; incisor with single rounded cusp Order Isopoda Latreille, 1817 on right side and 3 small teeth on left side; lamina dentata Family Anthuridae Leach, 1814 unserrated on both sides (Fig. 2A, B). Genus Caenanthura Kensley, 1978 Maxilla with 1 prominent and 4 smaller spines apically (Fig. 2C). *Caenanthura engimatica (Kensley and Reid, 1984) Maxilliped 4 segmented; endite absent; palp articles 1-3 (Figs. 1-4) fused, with 3 simple setae along with lateral margin and 2 Arabanthura engimatica Kensley and Reid, 1984: 675. long simple setae at distal margin; articles 4-5 fused, with 3 Caenanthura engimatica Poore, 2001: 108. simple setae laterally (Fig. 2D). Pereopod 1 subchelate, robust; basis bulbous, as long as Material examined. Korea: 6♀♀, Jeollanam-do: Wando- width, with 2 plumose setae and 4 simple setae; ischium gun, Soan-myeon, Maengseon-ri (34°10′49″N, 126°38′07″ with simple setae on ventral and dorsal margins; merus with E), 27 May 2017; 1♀, Gyeongsangnam-do: Tongyeong-si, simple setae along with ventral margin and anterodistal Hansan-myeon, Yongho-ri (34°44′44″N, 128°28′07″E), depth angle; carpus triangular, crenulated and produced on pos­ 10 m, van Veen grab, 24 Mar 2014; 2♀♀, Chubong-ri (34° terodistal margin, 1 strong fringed proximal spine and nu­ 45′42″N, 128°32′30″E), depth 8 m, van Veen grab, 19 Mar merous simple setae on ventral margin; propodus swollen; 2014; 1♀, Yeomho-ri (34°48′04″N, 128°26′20″E), 18 Oct palm crenulated and with 1 strong fringed proximal spine 2014; 1♀, Sanyang-eup, Yeongun-ri (34°48′04″N, 128°26′ an numerous simple setae; unguis longer than other pereo­ 20″E), 20 Mar 2014; 2♀♀, Geoje-si, Nambu-myeon, Jeogu- pods. Pereopod 2 basis subequal in length to ischium; is­ ri (34°43′50″N, 128°35′30″E), depth 10 m, van Veen grab, chium, merus, carpus, and propodus with long simple setae 17 Oct 2014. on ventral margin; ischium and mers with simple setae on Description. Body 9 times as long as wide, slender, and dorsal margin; propodus with 1 short robust spine on plam. smooth; length 9.1 mm. Cephalon 0.9 times longer than Pereopod 3 similar to pereopod 2; basis with 1 plumose width, with rostrum extending as long as anterolateral lobes, seta. Pereopods 4-7 similar to each other; bases with 1 or 2 without eyes. Proportions of body segments: cephalon< plumose setae on dorsal margin; ischia with 1 simple seta on pereonite 1pere­ dorsal margin and numerous simple setae on ventral margin; onite 5>pereonite 6>pereonite 7

Korean name: *등홈무목마디벌레 (신칭)

Anim. Syst. Evol. Divers. 34(3), 174-180 175 Sung Hoon Kim, Seong Myeong Yoon

A B

C

D

A, B

C

D, E E

Fig. 1. Caenanthura engimatica, female. A, Habitus, dorsal view; B, Habitus, lateral view; C, Pleotelson; D, Antennule; E, Antenna. Scale bars: A-C=1 mm, D, E=0.2 mm.

176 Anim. Syst. Evol. Divers. 34(3), 174-180 A New Report of Caenanthura from Korea

A B

C

D

A, B

C, D

Fig. 2. Caenanthura engimatica, female. A, Right mandible; B, Left mandible; C, Maxilla; D, Maxilliped. Scale bars: A-D=0.2 mm. outer margin and numerous plumose setae on outer margin the former vs. zero in the latter), and the morphology of the (Fig. 4F, G). carpus (with produced posterodistal margin in the former vs. Habitat. Mud flat. without that in the latter) (Barnard, 1925; Kensley, 1978). Distribution. Indian Ocean, Saudi Arabia, Korea (in this Caenanthura engimatica also differs from C. indica Ne­ study). goescu, 1980 by the number of mandibular palp articles (bi- Remarks. Caenanthura engimatica (Kensley and Reid, segmented palp article in the former vs. uni-segmented palp 1984) is similar to C. siamensis (Barnard, 1925) in terms of article in the latter), the length of the rostrum (as long as an­ the pereonites having dorsal pits. However, the former dif­ terolateral lobes in the former vs. much shorter than antero­ fers from the latter in terms of the segmented mandibular lateral lobes in the latter), and the presence of the dorsal pit palp (bi-segmented palp article in the former vs. uni-seg­ on the pereonites (vs. absence in the latter) (Negoescu, 1980). mented palp article in the latter), the number of simple setae Caenanthura engimatica can be distinguished from C. on the 1-3 fused article of the maxillipedal palp (three in gutui (Negoescu, 1997) by the presence of dorsal pits on the

Anim. Syst. Evol. Divers. 34(3), 174-180 177 Sung Hoon Kim, Seong Myeong Yoon

A

B

C

D

E

F

A, B G C-G

Fig. 3. Caenanthura engimatica, female. A, Pereopod 1; B, Pereopod 2; C, Pereopod 3; D, Pereopod 4; E, Pereopod 5; F, Pereopod 6; G, Pereopod 7. Scale bars: A-G=0.5 mm.

178 Anim. Syst. Evol. Divers. 34(3), 174-180 A New Report of Caenanthura from Korea

C B A

D E F

A-G G

Fig. 4. Caenanthura engimatica, female. A, Pleopod 1; B, Pleopod 2; C, Pleopod 3; D, Pleopod 4; E, Pleopod 5; F, Uropodal exopod; G, Uropodal endopod. Scale bars: A-G=0.5 mm.

Anim. Syst. Evol. Divers. 34(3), 174-180 179 Sung Hoon Kim, Seong Myeong Yoon pereonites (vs. absence in the latter) and the number of the University (2017) and the National Institute of Biological maxillipedal palp articles (bi-segmented in the former vs. Resources (NIBR), funded by the Ministry of Environment 3-segmented in the latter) (Negoescu, 1997). (MOE) of the Republic of Korea (NIBR 201801202). Caenanthura engimatica differs from C. ibex Bamber, 2008 in terms of the presence of dorsal pits on the pereonits (vs. absence in C. ibex) and the shape of lacinia dentate on REFERENCES mandible (smooth in the former vs. serrated in the latter) (Bamber, 2008). Bamber RN, 2008. New species of anthurid and arcturid iso­ Caenanthura engimatica is similar to C. koreana Song pod (Crustacea: : Isopoda) from Hong Kong. and Min, 2015 in body length and having 2 segmented man­ Journal of Natural History, 42:855-876. https://doi.org/ dibular palp and the rostrum as long as anterolateral lobes. 10.1080/00222930701850489

However, the former is distinguishable from the latter by the Barnard KH, 1925. A revision of the family Anthuridae (Crusta­ presence of dorsal pits on the pereonite (vs. absence in the cea Isopoda), with remarks on certain morphological pecu­ latter) and the number of maxillipedal palp articles (bi-seg­ liarities. Zoological Journal of the Linnean Society, 36:109- mented in the former vs. 3-segmented in the latter) (Song 160. https://doi.org/10.1111/j.1096-3642.1925.tb01849.x and Min, 2015). Chew M, Rahim AA, bin Haji Ross O, 2014. Tinggianthura alba: a new genus and species of Anthuridae (Isopoda, Cy­ The Korean materials of C. engimatica corresponded mothoida, Anthuroidea) from Pulau Tinggi, Johor, Malaysia well with the original description of the species by having with an updated key to the genera of Anthuridae. PLoS One, the rostrum as long as anterolateral lobes, bi-segmented 9:e99072. https://doi.org/10.1371/journal.pone.0099072 mandibular palp, 4-segmented maxilliped, one simple seta Kensley B, 1978. Five new genera of anthurid isopod crusta­ - on 1 3 fused article of the maxillipedal palp, dorsal pits on ceans. Proceedings of the Biological Society of Washing­ - pereonites 4 6, and the carpus of pereopod 1 having pro­ ton, 91:775-792. duced posterodistal margin (Kensley and Reid, 1984). How­ Kensley B, Reid J, 1984. Arabanthura enigmatica, a new genus ever, these Korean materials have some minor differences and species of anthurid isopod from the Arabian Gulf. Pro­ from the original description in the presence of the dorsal ceedings of the Biological Society of Washington, 97:674- pit on pereonite 1 (absent in the former vs. present in the lat­ 680. ter), the number of the simple seta on the mandiblular palp Negoescu I, 1980. Littoral anthuridean isopods (Isopoda, An­ (each article of the mandiblular palp with 1 simple seta in thuridea) from the northwestern Indian Ocean. Travaux du the former vs. only distal article with 1-2 simple setae in the Museum d’Histoire Naturelle Grigore Antipa, 22:401-420. latter), and the number of simple setae on the distal margin Negoescu I, 1997. Isopoda Anthuridea. Results of the Zoolog­ of pleotelson (five in the former vs. six in the latter) (Kensley ical Expedition organized by “Grigore Antipa” Museum in and Reid, 1984). These minor differences are regarded as the Indonesian Archipelago (1991). I. Peracarida (Crusta­ variations of regional populations. cea). Travaux du Museum d’Histoire Naturelle Grigore An­ tipa, 38:177-251. Poore GC, 2009. Leipanthura casuarina, new genus and spe­ Revised key to known species of the genus cies of anthurid isopod from Australian coral reefs without Caenanthura (based on Song and Min, 2015) a “five-petalled” tail (Isopoda, , Anthuroidea). 1. Dorsal pits absent on pereonites······································· 2 ZooKeys, 18:171-180. https://doi.org/10.3897/zookeys.18. - Dorsal pits present on pereonites······································ 5 198 2. Rostrum much short than anterolateral lobes········C. indica Poore GCB, 2001. Families and genera of Isopoda Anthuridea. - Rostrum as long as antherolateral lobes···························· 3 Issues, 13:63-173. 3. Maxillipedal palp with 2 articles······························C. ibex Song JH, Min GS, 2015. Two new species, Caenanthura ko-

- Maxillipedal palp with 3 articles······································· 4 reana sp. nov. and Apanthura koreaensis sp. nov. (Crus­ 4. ‌Distal article of mandibular palp 3 times longer than tacea: Isopoda: Anthuridae) from South Korea. Zootaxa, proximal article··················································C. koreana 3937:362-376. https://doi.org/10.11646/zootaxa.3937.2.7 - ‌Distal article of mandibular palp 2 times longer than Wägele JW, 1989. Evolution und phylogenetisches System der Isopoda. Stand der Forschung und neue Erkenntnisse. Zoo­ proximal article······················································ C. gutui logica (Stuttgart), 140:1-262. 5. Mandibular palp with single article················C. siamensis WoRMS, 2018. World Register of Marine Species [Internet]. - Mandibular palp with 2 segmented article····C. engimatica Accessed 12 Jun 2018, . ACKNOWLEDGMENTS Received April 26, 2018 Revised July 16, 2018 This study was supported by the research funds from Chosun Accepted July 16, 2018

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